INFLUNCE OF DEPOSITION TIME ON THE STRUCTURAL AND OPTICAL PROPERTIES OF CdS THIN FILMS SYNTHESIZED BY CHEMICAL BATH DEPOSITION (CBD)

Abstract

CdS thin films were deposited on the glass substrates by using chemical bath deposition method (CBD) at temperature of 800C. The effect of deposition time on the structural and optical properties of CdS thin film was studied. The bath containing 3CdSO4.8H2O, CS(NH2)2, distilled water and ammonia(25%) as starting materials. Five samples were deposited for different deposition time (30, 40, 50, 60 and 70) min. The structural and optical properties of CdS thin films were investigated using X-ray powder diffraction (XRD), and ultraviolent visible (UV-vis) spectroscopy respectively. It was confirmed from X-ray diffraction analysis that all the structures are with (111) plane as a preferred orientation, confirms CdS thin films are cubic structure formed and peaks (101) plane showed the formation of hexagonal structure. Hence, the CdS thin films have the mixed structure phase. The crystal structural parameters such as crystal size, micro strain, dislocation density were calculated and the results confirmed that the deposition time had visible influence on the structural parameters. CdS thin films calculated a crystallite size in the range of (10.47-13.34nm) with the deposition time of (30-70min). The UVVisible spectroscopy study showed that the optical band gap energy for CdS thin films were find to be in the range of (1.89-1.64ev